辽河口沉积物环境要素时空动态及影响因素分析

Temporal and Spatial Variation Patterns of the Environmental Elements in the Sediments of the Liaohe Estuary and the Related Influencing Factors

以辽河口为研究区域,利用遥感影像数据、现状调查数据和历史监测数据,系统地分析了辽河口沉积物质量历史变化趋势和空间分异规律,并进一步研究不同海域使用类型和不同植被演替阶段对沉积物环境要素分异特征的影响.结果表明,辽河口区域沉积物质量总体良好,各要素平均含量均符合一类沉积物质量要求;沉积物营养元素呈现显著的带状分布规律,重金属元素空间分布具有一定随机性,未呈现显著规律;不同海域使用类型对沉积物污染物富集的影响具有一定差异显著性,说明重金属及污染物的分布受到人类活动的影响,具有一定的随机性;植被不同演替阶段下主控因子具有显著差异,初级阶段主要受盐度控制,随着由盐生植被向陆生植被逐渐过渡,植被分布特征与总有机碳(TOC)、总氮(TN)和总磷(TP)的内在联系逐渐增大,同时重金属等污染物含量与植被群落内在联系并不显著.

Remote sensing images,field survey data,and historical monitoring data are collected to analyze the historical change trend and spatial variation rules of sediment quality of the Liaohe Estuary and further investigate the effects of sea-area utilization type and vegetation succession stage on the variation patterns of environmental elements in the sediments.The results showed that the quality of the sediments in the Liaohe Estuary is overall favorable,and the average contents of various elements all satisfy the quality standards of first-grade sediments.The nutritive elements in the sediments exhibit obvious zonal distribution patterns,while heavy metals are randomly distributed and exhibit no obvious patterns.The effect of sea-area utilization type on the enrichment of pollutants in the sediments exhibits certain significant differences,suggesting that the distributions of heavy metals and pollutants are subject to human activities and exhibit certain randomness.The main control factors are significantly different at different vegetation succession stages.Specifically,the vegetation distribution in the initial succession stage is mainly affected by salinity;with the transition from halophytic vegetation to terrestrial vegetation,the inherent correlation between vegetation distribution characteristics and the contents of total organic carbon,total nitrogen,and total phosphorus increase gradually.Meanwhile,the content of heavy-metal pollutants exhibits no significantly inherent correlation between the distributions of the plant community.